杭电HDOJ1012 u Calculate e

#include<stdio.h>

int f(int n)

{

 return n<=1?1:n*f(n-1);

}

int main()

{

 const int n=9;

 double sum=0;

 printf("n e\n- -----------\n");

 for(int i=0;i<=n;i++)

 {

  //printf("1/f(%d)=%f\n",i,1/(double)f(i));

  //if(!i)

  sum+=1/(double)f(i);

  if(i<=1)printf("%d %d\n",i,(int)sum);

  else if(i==2)printf("%d %.1f\n",i,sum);

  else

  printf("%d %.9f\n",i,sum);

 }

 return 0;

}